Why Don’t All Cars Have Gas Tanks on the Same Side?

Updated: Feb. 15, 2023

The position of a car's fuel door (if you can actually remember where it is) remains one of the greatest unsolved motoring mysteries.

Why-Do-Cars-Have-Gas-Tanks-on-the-Left-or-RightBACHTUB-DMITRII/ShutterStock

Do car company engineers draw straws to decide what side of the car the fuel door goes on? No—but they might as well. If you’ve ever been stuck in a long line for gas and spent the time wondering why your fuel door is on the left (or right), don’t expect a succinct answer.

According to Ford spokesman Mark Schirmer, as reported on theAllstateBlog, engineers are free to place fuel doors on the side of the car that offers the easiest packaging. And while one on each side would be rather convenient, we’re not likely to see dual fuel doors anytime soon—there’s neither the room nor the demand for them.

“The placement of the fuel door is mainly a factor of fuel tank design, location, and underbody packaging,” Nissan’s Steve Yaeger told theAllstateBlog. “With all of the structure and components located underneath the vehicle, (engineers) would quickly encounter restrictions in trying to route the filler tube to the same side on every vehicle.”

Why-Do-Cars-Have-Gas-Tanks-on-the-Left-or-Rightwelcomia/ShutterStock

Schirmer says Americans prefer fuel doors on the left side of their cars, probably because it makes it easier for them to place their car’s left fender close to the fuel pump. For this reason, it’s possible that drivers in the U.K., Australia, New Zealand, India, and other countries who drive on the left side of the road favor a right-hand-side fuel door. But there’s nothing to confirm that driver preference is a factor. There are regulations about where the fuel door should be positioned, but these don’t specify the right or left side of the car. (Current regulations regarding car fuel systems demand the filler be at the widest part of a car, inboard of any crumple zones, and safe from dripping onto any hot exhaust bits or electrical wiring.)

Robert Frank, writing for PBS Newshour, puts forward the “equilibrium” arguments, suggesting that if all cars had fuel doors on the same side, 50 percent of the pumps in the gas station would be unused, and we’d all spend even more of our time waiting in line to get gas. (Good point!)

Oh, and if you can’t remember the location of your fuel door (and if we’re completely honest, most of us will have to take a second and think about that before we answer), simply look at the little diamond-shaped arrow on the fuel gauge on your dashboard—it points to the side of the car where the fuel door is. Do it before you pull up to the pump, to avoid the embarrassment of having to get back into your car and drive to another pump. As far as where to buy the gas, make sure you don’t find yourself at the most hated gas station in America.